Waster discharge pipe size ? - Plumbers say tear up my new slab to up size risers

[Mace Canute]

Just because he lives outside of where inspections occur, does not mean the code officials are clueless as to what works and what doesn't in their area.

I personally would be shocked if there are any issues from 3" off the thrones to a 4" main. It's how many are done here and have been so for many years. Very seldom are there issues and those issues are never resulting from the 3" off the toilets.

So true. It's when stuff other than bodily waste and toilet paper is flushed that problems occur.

 

[Sysop]

Yea, I just never seen it on a 3" drop to a 4" main. Simply put, the wider the pipe, the shallower and slower the water moving through it. Or; the more water it takes to keep things moving. Just like a river, a wide river moves slow. Route it into a narrow canyon and things speed up.

4" is where the problems always develop. That's where most non-normal things stop moving and catch other things and begin a blockage. Again, like a river; a wide slow river will deposit things along the banks. A fast river will sweep the banks clear of everything.

 

[kidr]

I think a lot of the old codes were written for cast iron pipe. plastic is a different animal. I've never had a clog in plastic pipe, only at the fixture.

 

[kenmac]

I think a lot of the old codes were written for cast iron pipe. plastic is a different animal. I've never had a clog in plastic pipe, only at the fixture.

well, I can guarantee you ,plastic (PVC) will clog.

 

[square1]

...the builder may have actually FIRED THE WRONG PLUMBER?
3" is fine!

:yes:

 

[Budweiser John]

Any toilet contense that dumps to a sanitary lift pump will eventually be discharged through a 2" pipe.
It's common to up size the riser fot a toilet installed on a concrete floor as the riser is typically left proud of the finished pour and later cut flush with the floor elevation. The closet flange is of the 'male'type that cements inside the riser and not over the external pipe diameter.
Drainage mains and laterals are sized by the number of 'DFUs' (drainage fixture units) each branch must accomidate and inspection or not should be considered to insure a poop free system

B John

 

[EddieWalker]

3 inch is pretty standard and anybody who says it isn't is either clueless or dishonest.

The trap inside the toilet is only an inch and a half, maybe two inches at the most. If it gets through the internal trap inside the toilet, it's never going to have any issues going into a three inch line.

What size are your vents and how far from the toilet are they?

Pictures would be really helpful.

Why was the original plumber fired?

 

[dadster4]

You shouldn't need to increase to 4" until you pick up the third toilet down the line, up till then 3" is all you need!

 

[vpracer]

Thanks for all the posts guys. No inspections but the new plumber is going with the 3" and is now comfortable with it. I don't know the size of the vents, hoping the original plumber managed that ok. The first plumber has some difficulty getting the pipes in the walls so the builder is having to shim the walls since pipes stick out a tad. Honestly, I'm amazed he got it that close. Foundation is crazy full of steel. So the builder said the concrete guys liked the first plumber because he hand dug beams. The plumber we have now, supposedly better, used a trencher and messed up the concrete guys beams. Who knows. A couple pics of progress and my safe room.

 

[TheMan419]

Or "go with the code requirement" which are non-existent in his area.

Sad how people will post in a thread without reading it.

Even if there was code, that is the MINIMUM requirement. Might be that x meets code but if you go up to y the whole thing just works better.

I have no idea what the right answer is, but having read the thread I know the right answer is not for OP to call the inspector